This application claims the priority of German patent application Serial No. 198 57 576.9 filed Dec. 14, 1998. The disclosure of the above-referenced German patent application, as well as that of each U.S. and foreign patent and patent application mentioned in the specification of the present application, is incorporated herein by reference.
The invention relates to improvements in apparatus for making composite rod-shaped commodities, such as filter cigarettes, cigars, cigarillos and the like. More particularly, the invention relates to improvements in apparatus wherein successive groups of coaxial rod-shaped articles are connected to each other, end-to-end, by flexible bands or strips which are convoluted around abutting end portions of coaxial articles. As a rule, or at least in many instances, one side of each strip or band (hereinafter called uniting band) is coated with a suitable adhesive so that the convoluted uniting band adheres to and forms a tubular wrapper or envelope around the abutting end portions of the thus joined or assembled composite rod-shaped assemblies.
It is well known to make filter cigarettes in a so-called tipping machine wherein rod-shaped filter mouthpieces of double unit length are placed between pairs of coaxial plain cigarettes of unit length and an adhesive-coated uniting band is convoluted around each mouthpiece of double unit length as well as around the adjacent (inner) end portions of the respective plain cigarettes of unit length. The resulting filter cigarettes of double unit length are severed midway across the tubular wrappers (convoluted uniting bands) to yield pairs of filter cigarettes of unit length. One filter cigarette of each pair is inverted end-for-end and is placed between the non-inverted filter cigarettes to form therewith a row of parallel filter cigarettes which are conveyed sideways to a testing station and thereafter to storage or to a packing machine. Reference may be had to commonly owned U.S. Pat. No. 5,135,008 granted Aug. 4, 1992 to Erwin Oesterling et al. for xe2x80x9cMETHOD OF AND APPARATUS FOR MAKING FILTER CIGARETTESxe2x80x9d.
As a rule, the adhesive-coated uniting bands are convoluted around two or more coaxial rod-shaped articles during sidewise travel of the articles in a so-called rolling channel between two surfaces at least one of which moves relative to the other surface. For example, the rolling channel can be defined by the convex peripheral surface of a rolling drum and the complementary concave surface of a stationary rolling member. The inlet of the rolling channel receives successive groups of coaxial rod-shaped articles, and each such group already carries or can carry and adhesive-coated uniting band. The latter is convoluted around the respective group while the group rolls in the channel due to the selected difference between the speeds of the surfaces which bound the channel. Each group can be caused to turn about its longitudinal axis once or more than once depending, e.g., upon the size of the uniting band and/or upon the length of the interval of time which is required to ensure reliable adherence of the convoluted uniting band to the rod-shaped articles of the respective group and/or reliable adherence of convolutions of the rolled-up uniting band to each other.
Heretofore known apparatus for convoluting uniting bands around groups of two or more coaxial rod-shaped articles can be categorized in dependency upon their design and/or mode of operation. A first category employs a rotary drum-shaped conveyor and a stationary block or belt; the stationary part cooperates with the conveyor to define the aforementioned channel wherein successive groups of rod-shaped articles roll from the inlet to the outlet with attendant rolling of the uniting bands around the abutting end portions of the rod-shaped articles in the respective groups. Apparatus of the just outlined character are disclosed, for example, in German patents Nos. 65 90 64, 96 03 47 and 37 02 915.
German patent No. 65 90 64 discloses a filter tipping machine wherein a first rotary drum is provided with peripheral flutes for delivery of groups of coaxial plain cigarettes and filter rod sections into contact with adhesive-coated uniting bands being delivered by a second rotary drum-shaped conveyor which cooperates with a band to define an arcuate channel wherein the uniting bands are convoluted around the respective groups of coaxial rod-shaped articles.
German patent No. 96 03 47 discloses a filter tipping machine wherein the peripheral surface of a drum-shaped conveyor is provided with flutes for groups of coaxial plain cigarettes and filter rod sections. The peripheral surface turns in a first direction and cooperates with a driven belt to define a rolling channel. The belt is driven in a second direction counter to the first direction and such belt further serves to deliver discrete uniting bands to the inlet of the rolling channel; each such band is caused to adhere to and is convoluted around the oncoming group of coaxial plain cigarettes and one or more filter mouthpieces.
German patent No. 37 02 915 discloses a filter tipping machine wherein groups of coaxial plain cigarettes and filter rod sections are contacted by adhesive-coated uniting bands upstream of the inlet of the rolling channel. The groups and the respective uniting bands are delivered by a rotary drum-shaped conveyor which defines the rolling channel with a stationary block-shaped rolling member. The groups which approach the inlet of the channel are engaged by ribs or analogous protuberances provided on rollers or drums which frictionally engage the groups on the rotating conveyor and are thus entrained in a direction toward the inlet while moving at a speed less than the peripheral speed of the conveyor. This causes the groups to roll around their respective axes during advancement from the inlet toward the outlet of the rolling channel.
The aforedescribed filter tipping machines are merely three examples of presently known apparatus wherein uniting bands are caused to connect groups of coaxial rod-shaped articles by means of convoluted adhesive-coated uniting bands. All such apparatus exhibit the serious drawback that at least one of the surfaces bounding the rolling channel is stationary. This can affect the quality and/or the appearance of the thus obtained assemblies of rod-shaped articles and convoluted uniting bands, especially as a result of abrupt initiation of the rolling step at the inlet of the channel. The force which acts upon the groups entering the channel is quite pronounced, and such force does not diminish as the rolling operation progresses. The filter tipping machine which is disclosed in the aforementioned German patent No. 37 02 915 exhibits the additional drawback that the rolling channel is bounded by two stationary surfaces and the parts which are provided with such stationary surfaces cannot yield at all, i.e., the material of such parts is devoid of any elasticity. This can greatly affect the appearance and/or the integrity of the assemblies of coaxial rod-shaped articles (such as plain cigarettes and filter rod sections) and the convoluted uniting bands, especially if the tipping machine is to be operated at a relatively high speed. The engagement of successive groups by the aforementioned protuberances or projections in the form of ribs or the like, which engage successive groups while moving at a speed well below that of the rotary drum-shaped conveyor, can also result in defacing of and/or in structural damage to the ultimate products.
A second category of presently known apparatus for convoluting uniting bands around groups of coaxial rod-shaped articles differs from the aforedescribed apparatus in that the rolling channel is defined by two moving surfaces provided on driven endless belts. The belts can yield, at least to a certain extent, to thus reduce the likelihood of damage to the rod-shaped articles and to the uniting bands during advancement toward and through the rolling channel. Reference may be had, for example, to British patent No. 1 046 489. However, to the best of applicants"" and his assignee""s knowledge and belief, apparatus of the type disclosed in the British patent failed to gain acceptance by the makers of filter tipping and like machines.
More specifically, the British patent proposes to provide a rolling channel between the upper reach or stretch of a lower endless belt conveyor and the lower reach or stretch of an upper belt conveyor. The lower belt conveyor is driven at a speed below that of the upper belt conveyor. A drum is employed to deliver groups of coaxial plain cigarettes and filter rod sections onto the upper reach of the lower belt conveyor ahead of the front end turn of the upper belt conveyor, i.e., ahead of the actual inlet of the rolling channel. The lower belt conveyor delivers successive groups toward and into contact with the lower reach of the upper belt conveyor, i.e., into the inlet of the rolling channel. The upper belt conveyor carries the uniting bands which contact the oncoming groups at the inlet of and are convoluted around such groups during travel in the rolling channel. At the same time, the groups are pushed along the rolling channel by entraining elements which are advanced at a speed higher than that of the lower belt conveyor but below that of the upper belt conveyor. The entraining elements serve to advance the assemblies of groups of coaxial rod-shaped articles and convoluted uniting bands beyond the outlet of the rolling channel, along a stationary guide, and into the receptacles of a rotary drum-shaped take-off conveyor.
One serious drawback of the just described patented apparatus is that the uniting bands come into contact with the respective groups of coaxial rod-shaped articles only at the inlet of the rolling channel. Moreover, the patented apparatus is quite complex because it must be equipped with means for driving the upper belt conveyor at a first speed, with means for driving the lower belt conveyor at a different second speed, and with means for driving the entraining elements at a still different third speed. Still further, the three different speeds must be selected and maintained unchanged with a very high degree of accuracy in order to ensure that each uniting band comes into initial contact with a group of coaxial rod-shaped articles exactly at the inlet of the rolling channel. The numerous driving means, belt conveyors, drums and entraining elements contribute to the bulk, complexity as well as initial and maintenance cost of the patented apparatus. It has been found that the entraining elements are especially likely to affect the quality and/or the appearance and/or other characteristics of the ultimate products in that they subject the groups of coaxial rod-shaped articles to the action of pronounced forces often greatly exceeding those which can be withstood by the commodities being processed in filter tipping and analogous machines. It must be borne in mind that the wrappers of plain cigarettes are made of thin sheet material (cigarette paper) and that the wrappers of filter rod sections as well as the uniting bands are also made of a sheet material whose resistance to tearing is relatively low. The material of the uniting bands is known as tipping paper and is often made of artificial cork or the like.
An object of the invention is to provide an apparatus which can be used in filter tipping and analogous machines as a superior substitute for presently known apparatus serving to convolute uniting bands around groups of coaxial rod-shaped articles, such as plain cigarettes of unit or multiple unit length and filter rod sections of unit or multiple unit length.
Another object of the invention is to provide a novel and improved system of conveyors for groups of rod-shaped articles and for uniting bands for use in the above outlined apparatus.
A further object of the invention is to provide an apparatus wherein the constituents of assemblies of rod-shaped articles and uniting bands are not subjected to pronounced stresses, even if the apparatus is operated at a speed which is required in modern high-speed filter tipping and analogous machines.
An additional object of the invention is to provide an apparatus which can reliably and predictably deliver rod-shaped articles and uniting bands into the rolling channel and can predictably transport finished products from the outlet of such channel.
Still another object of the instant invention is to provide a novel and improved method of supplying the constituents of filter cigarettes, cigars, cigarillos and analogous rod-shaped smokers"" products into and of evacuating finished rod-shaped commodities from a tipping machine.
A further object of the invention is to provide an apparatus wherein certain constituents (such as rotary drum-shaped conveyors) can perform several functions to thus contribute to the compactness, simplicity, lower cost and reliability of the apparatus.
Another object of the invention is to provide an apparatus which can be put to use in existing filter tipping and analogous machines in lieu of conventional apparatus including those described in the aforediscussed U.S., German and British patents.
An additional object of the invention is to provide an apparatus wherein the articles entering into and advancing in the rolling channel need not be contacted and acted upon by any rigid parts which could adversely affect the appearance and/or other desirable characteristics of filter cigarettes or analogous smokers"" products.
Another object of the invention is to provide novel and improved drum-shaped and other conveyors for use in the above outlined apparatus.
A further object of the invention is to provide an apparatus which can be put to use in modern high-speed production lines for the making of filter cigarettes, cigars, cigarillos or other filter-tipped rod-shaped smokers"" products of the tobacco processing industry.
Still another object of the invention is to provide a novel and improved method of making filter cigarettes, cigars or cigarillos.
The invention resides in the provision of an apparatus for convoluting flexible strips (such as the aforementioned adhesive-coated uniting bands) around rod-shaped commodities (such as two or more rod-shaped articles of the tobacco processing industry which are to be connected with each other end-to-end by convoluting a strip around the abutting end portions of the articles). The improved apparatus comprises a rolling unit including first and second walls which define an elongated rolling channel having an inlet and an outlet, and means for moving at least one of the wall in a direction from the inlet toward the outlet so that a strip adjacent a commodity which is admitted into the inlet is convoluted around such commodity on its way toward the outlet of the rolling channel (namely while the commodity is caused to move sideways as a result of movement of at least one of the walls relative to the other wall). The apparatus further comprises means for introducing successive commodity-strip assemblies of a series of such assemblies into the inlet; such introducing means includes a rotary drum-shaped feeding conveyor which is arranged to admit successive commodities essentially directly into the inlet of the rolling channel.
As already mentioned above, the commodities can constitute groups of coaxial rod-shaped articles of the tobacco processing industry, and the strips can constitute adhesive-carrying uniting bands each of which adheres to the respective group not later than at the outlet of the rolling channel.
It is presently preferred to design the rolling unit in such a way tha each of the walls constitutes an elongated stretch or reach of an endless (one-piece or composite) flexible conveyor belt.
In accordance with an important and highly advantageous feature of the invention, one of the belts is trained over the rotary drum-shaped feeding conveyor. Such one belt has an end turn which is located at the inlet of the rolling channel and is trained over the feeding conveyor in such a way that the axis of the end turn coincides with the axis of the feeding conveyor. The latter can include a portion which constitutes, or which can be said to constitute, a pulley for the end turn of the one belt. The one belt can receive motion directly from the feeding conveyor.
The improved apparatus further comprises means for removing successive assemblies, with the strips convoluted around the respective rod-shaped commodities, from the outlet of the rolling channel. The removing means can comprise a rotary drum-shaped receiving conveyor which can be a mirror image of the feeding conveyor. The one conveyor belt which receives motion from the feeding conveyor is preferably mounted in such a way that its first end turn is trained over the feeding conveyor and that its second end turn is trained over the receiving conveyor. The axis of the second end turn can coincide with the rotational axis of the receiving conveyor. The arrangement can be such that the receiving conveyor includes a first rotary portion serving to receive successive assemblies from the outlet of the rolling channel, and a second rotary portion coaxial with the first portion and including or constituting a pulley for the second end turn of the one conveyor belt. The first and second portions of the receiving conveyor can be mounted for rotation with and relative to each other about a common axis. The re-receiving conveyor or the removing means can further comprise means for rotating the first portion of the receiving conveyor at a first peripheral speed and for rotating the second portion of the receiving conveyor at a second peripheral speed which is higher than the first peripheral speed. Alternatively, the receiving conveyor or the removing means can comprise means for rotating the first and second portions of the receiving conveyor at identical speeds.
The removing means can be constructed and assembled and mounted in such a way that it can accept successive assemblies at least substantially directly from the outlet of the rolling channel.
If the rolling unit comprises one endless belt, such one belt can be trained over the feeding and receiving conveyors. If the rolling unit comprises two endless conveyor belts, one of these belts can be trained over the feeding and receiving conveyors.
The peripheral surface of the rotary drum-shaped receiving conveyor can be provided with receptacles for discrete assemblies of two or more rod-shaped commodities and strips convoluted around the respective commodities; each such receptacle can comprise an abutment and at least one suction port adjacent the abutment to attract an assembly to the abutment. The abutments of the receptacles can constitute elongated ribs which are at least substantially parallel to the rotational axis of the receiving conveyor.
Analogously, the peripheral surface of the rotary drum-shaped feeding conveyor can be provided with receptacles for successive groups of two or more coaxial rod-shaped commodities each. Each such receptacle can comprise an abutment and at least one suction port adjacent the abutment to attract a rod-shaped commodity to the abutment. The abutment of each receptacle at the peripheral surface of the feeding conveyor is or can be at least substantially parallel to the rotational axis of the feeding conveyor.
The receptacles at the periphery of the feeding conveyor can be equidistant from each other (as seen in the circumferential direction of the feeding conveyor), the same as the receptacles at the periphery of the receiving conveyor. The distances between neighboring receptacles of the feeding conveyor can exceed or can be less than or can at least approximate the distances between neighboring receptacles of the receiving conveyor.
The feeding conveyor can be provided or can cooperate with means for introducing into the inlet of the rolling channel groups of rod-shaped commodities simultaneously with the strips which are convoluted in the rolling channel. To this end, the feeding conveyor can comprise first (e.g., pneumatically operated) receptacles for delivering to the inlet groups of coaxial rod-shaped commodities, and second (e.g., pneumatically operated) receptacles for delivering to the inlet strips, one for each of the groups of coaxial commodities delivered by the first receptacles.
Each wall of the rolling unit is preferably provided with a smooth strip-contacting surface confronting the rolling channel. Thus, if each of these walls constitutes a reach or stretch of an endless conveyor belt, each such conveyor belt has a smooth surface which comes in contact with successive groups of coaxial rod-shaped articles and/or with successive strips in the rolling channel.
The aforementioned moving means can include discrete first and second moving devices one of which can drive one of the belts at a first speed and the other of which can drive the other belt at a second speed different from the first speed.
Still further, the improved apparatus can comprise means for heating at least one of the walls, i.e., for heating at least one of the conveyor belts if each wall forms part of a discrete belt. The means for heating can comprise one or more electrically operated heating devices or one or more hydraulic or pneumatic heat exchangers. For example, the heating device or devices can ensure that the bond between the adhesive-coated side of a strip and the adjacent portions of peripheral surfaces of the rod-shaped constituents of the respective assembly (or between the overlapping convolutions of a strip) exhibits a requisite strength when the convoluted strip reaches the outlet of the rolling channel.
The single endless conveyor belt or one of two such belts can constitute a composite belt, i.e., a belt having two or more neighboring but at least slightly spaced-apart relatively narrow belts which are disposed in parallel planes. Thus, at least one of the walls forming part of the rolling unit can consist of two or more elongated strip-shaped portions extending in a direction from the inlet to the outlet of the rolling channel.
The novel features of the apparatus which are considered as characteristic of the present invention are set forth in particular in the appended claims. The improved apparatus itself, however, both as to its construction and the modes of assembling and operating the same, together with numerous additional important advantageous features and attributes thereof, will be best understood upon perusal of the following detailed description of certain presently preferred specific embodiments with reference to the accompanying drawings.